Does MSG Cause Headaches? Scientific Evidence and Facts

For decades, monosodium glutamate (MSG) has been blamed for causing headaches and various other symptoms. But does scientific evidence support this claim? This comprehensive guide examines the relationship between MSG and headaches, exploring what research really tells us about this controversial food additive.

What Is MSG (Monosodium Glutamate)?

Monosodium glutamate is a flavor-enhancing food additive commonly used in Asian cuisine, processed foods, and restaurant dishes. It appears as a white crystalline powder similar in appearance to salt or sugar.

MSG is derived from glutamic acid, a naturally occurring amino acid found in many foods including tomatoes, cheese, mushrooms, and seaweed. When added to food, MSG enhances the umami flavor—the savory, meaty taste that makes certain dishes more satisfying.

The Food and Drug Administration (FDA) classifies MSG as “generally recognized as safe” (GRAS), placing it in the same safety category as common ingredients like salt, pepper, and baking powder. Despite this classification, concerns about MSG’s health effects persist in popular culture.

Common Foods Containing MSG

MSG is found in numerous food products, including:

• Chinese food and other Asian cuisine
• Instant noodles and ramen
• Canned soups and broths
• Seasoning blends and spice mixes
• Frozen dinners and prepared meals
• Snack foods like chips and crackers
• Fast food items
• Processed meats and sausages
• Condiments and salad dressings

In the United States, products containing added MSG must list “monosodium glutamate” on their ingredient labels. However, foods naturally containing glutamate don’t require this disclosure. Outside the U.S., MSG may be identified by its E-number: E621.

The Origins of MSG Headache Concerns

The controversy surrounding MSG began in 1968 when a letter published in a medical journal described a set of symptoms the author experienced after eating at Chinese restaurants. These symptoms, which included numbness, weakness, and palpitations, became known as “Chinese Restaurant Syndrome.”

Since then, many people have reported experiencing headaches and other adverse reactions after consuming MSG-containing foods. These anecdotal reports led to widespread belief that MSG causes headaches, despite limited scientific evidence supporting this connection.

Does MSG Actually Cause Headaches? What Research Shows

Despite decades of concern, scientific research has not conclusively established a link between MSG consumption and headaches. Here’s what multiple studies have revealed:

Food-Based MSG Studies

A comprehensive 2016 review examined multiple human studies investigating the relationship between MSG and headaches. Researchers analyzed 13 different studies and found that:

• Six studies that examined MSG consumed with food found no significant association between MSG intake and headaches
• When MSG was consumed as part of normal meals, participants did not experience increased headache frequency compared to control groups
• The typical amounts of MSG consumed in everyday foods appeared safe for most people

High-Dose MSG Studies

Seven studies in the same review examined the effects of consuming MSG dissolved in liquid without food. These studies showed some participants reported headaches more frequently than those who consumed a placebo beverage.

However, researchers identified significant methodological problems with these studies:

• The studies were not properly blinded—participants could taste the difference between MSG and placebo solutions
• The doses used (typically 3 grams or more) were much higher than typical dietary consumption
• MSG was consumed on an empty stomach, which doesn’t reflect real-world eating patterns
• Knowledge that they had consumed MSG may have influenced participants’ symptom reporting

Official Medical Position

The International Headache Society previously listed MSG as a potential trigger for headaches. However, after reviewing additional research, the organization removed MSG from its list of causal factors for headaches due to insufficient evidence linking the two.

This decision reflects the current scientific consensus: there is not enough reliable evidence to conclude that MSG causes headaches in most people.

Understanding MSG Sensitivity

While large-scale studies haven’t confirmed a widespread link between MSG and headaches, some individuals report experiencing adverse reactions after consuming MSG. This phenomenon is sometimes called MSG sensitivity or MSG symptom complex.

Reported Symptoms of MSG Sensitivity

People who believe they are sensitive to MSG report various symptoms, including:

• Headaches or migraines
• Muscle tightness or tension
• Numbness or tingling
• Weakness or fatigue
• Facial flushing or pressure
• Chest discomfort
• Rapid heartbeat
• Nausea
• Sweating

The Challenge of Identifying True MSG Sensitivity

Determining whether someone is genuinely sensitive to MSG presents several challenges:

Expectation Effects: When people believe MSG will cause symptoms, they may be more likely to experience or notice those symptoms—a phenomenon known as the nocebo effect.

Multiple Ingredients: Foods containing MSG typically contain many other ingredients, additives, and compounds that could trigger reactions. Isolating MSG as the specific cause is difficult.

Natural Glutamate: Many foods naturally high in glutamate (like aged cheeses, tomatoes, and mushrooms) don’t trigger the same reported reactions, suggesting factors beyond glutamate content may be involved.

Dose-Dependent Effects: Most reported negative effects occur with very high doses (3+ grams) consumed without food, which doesn’t reflect typical eating patterns.

How MSG Works in Your Body

Understanding how your body processes MSG helps clarify why it’s unlikely to cause problems for most people.

MSG and the Blood-Brain Barrier

One concern about MSG stems from the fact that glutamic acid functions as a neurotransmitter in the brain. Some worried this might allow MSG to affect brain function negatively.

However, research has demonstrated that MSG consumed in food does not cross the blood-brain barrier—the protective membrane that prevents many substances from entering brain tissue from the bloodstream. This means dietary MSG cannot directly affect brain function or trigger neurological symptoms.

Normal Glutamate Metabolism

Your body already produces and uses glutamate as a standard amino acid. When you consume MSG, your digestive system breaks it down into glutamate and sodium, just as it would with naturally occurring glutamate from food sources.

The glutamate from MSG is indistinguishable from glutamate found naturally in foods. Your body metabolizes both types identically, which is why there’s no biochemical reason to expect different effects from added versus natural glutamate.

Average MSG Consumption Levels

Context matters when evaluating MSG safety. The average American consumes approximately 0.55 grams of MSG per day through their diet. This amount is far below the doses (3 grams or more) associated with reported adverse effects in research studies.

To put this in perspective:

• A typical serving of food containing MSG has less than 0.5 grams
• You would need to consume several large portions of MSG-heavy foods to approach potentially problematic doses
• Normal dietary intake appears safe for the vast majority of people

Other Potential Health Effects of MSG

Beyond headaches, researchers have investigated other possible health impacts of MSG consumption.

Weight and Metabolism

Some studies have suggested associations between regular MSG consumption and:

• Increased body weight
• Higher likelihood of being overweight or obese
• Metabolic syndrome symptoms

However, these associations may reflect overall dietary patterns rather than MSG specifically. People who consume more MSG tend to eat more processed foods generally, making it difficult to isolate MSG’s independent effects.

Blood Pressure

High doses of MSG have been associated with temporary increases in blood pressure in some studies. However, at typical dietary consumption levels, this doesn’t appear to be a significant concern for most people.

Appetite and Food Intake

MSG enhances food flavor, which could theoretically lead to increased food consumption. Some research suggests MSG might affect satiety signals, though findings are mixed and more research is needed.

Should You Avoid MSG?

For most people, consuming MSG in typical amounts found in food appears safe based on current evidence. However, you might choose to limit or avoid MSG if:

• You’ve consistently noticed adverse reactions after eating MSG-containing foods
• You want to reduce processed food consumption generally
• You prefer to avoid additives in your diet
• Your healthcare provider has recommended limiting MSG for specific health reasons

If You Think You’re Sensitive to MSG

If you believe you experience symptoms after consuming MSG, consider these steps:

Keep a detailed food diary: Record what you eat, when you eat it, and any symptoms you experience. This can help identify patterns and potential triggers.

Read ingredient labels carefully: In the U.S., added MSG must be listed on food labels as “monosodium glutamate.”

Ask about ingredients when dining out: Many restaurants, especially Asian establishments, will indicate which dishes contain MSG or can prepare dishes without it upon request.

Consider an elimination trial: Try avoiding MSG-containing foods for several weeks to see if symptoms improve, then carefully reintroduce them to observe effects.

Consult a healthcare provider: If you experience persistent or severe symptoms, speak with a doctor to rule out other potential causes and get personalized advice.

Identifying MSG on Food Labels

MSG added to processed foods must be listed in ingredients, but glutamate from natural sources may not be obvious. Here are terms that may indicate MSG or free glutamate presence:

• Monosodium glutamate
• Hydrolyzed vegetable protein
• Hydrolyzed plant protein
• Autolyzed yeast
• Yeast extract
• Soy protein isolate
• Textured protein
• Glutamic acid
• E621 (in countries using E-numbers)

The Broader Context: Processed Foods and Health

Whether or not MSG itself causes problems, foods containing added MSG tend to be highly processed items that may not support optimal health when consumed frequently. These foods often contain:

• High sodium levels
• Excessive calories
• Unhealthy fats
• Refined carbohydrates
• Multiple artificial additives
• Low nutrient density

Reducing consumption of these foods—regardless of their MSG content—can benefit your overall health. A diet focused on whole, minimally processed foods provides better nutrition and fewer additives overall.

What Triggers Headaches? Common Culprits

If you experience frequent headaches, many factors besides MSG could be responsible:

• Dehydration: Not drinking enough water is a common headache trigger
• Caffeine: Both excessive intake and withdrawal can cause headaches
• Alcohol: Particularly red wine and drinks high in congeners
• Lack of sleep: Poor sleep quality or insufficient sleep duration
• Stress: Emotional or physical stress commonly triggers tension headaches
• Skipped meals: Low blood sugar from not eating regularly
• Strong sensory stimuli: Bright lights, loud noises, or strong smells
• Certain foods: Aged cheeses, processed meats, artificial sweeteners
• Hormonal changes: Fluctuations during menstrual cycles
• Weather changes: Barometric pressure shifts
• Poor posture: Especially from prolonged computer use

If you experience chronic or severe headaches, consult with a healthcare provider to identify your specific triggers and develop an appropriate management plan.

The Bottom Line on MSG and Headaches

Current scientific evidence does not support a widespread connection between MSG consumption at typical dietary levels and headaches. While some individuals report sensitivity to MSG, well-controlled research studies have not confirmed a consistent, reproducible link.

Key takeaways include:

• MSG is considered safe by the FDA and major health organizations
• Scientific studies have not confirmed MSG as a headache trigger when consumed with food at normal amounts
• Reported negative effects typically involve very high doses consumed without food
• The average American consumes about 0.55 grams of MSG daily, well below amounts associated with adverse effects
• Individual sensitivity may exist but is difficult to confirm scientifically
• Many foods containing added MSG are processed items best consumed in moderation regardless
• If you believe you’re sensitive to MSG, you can choose to avoid it by reading labels and asking about ingredients when dining out

The MSG-headache connection appears to be more myth than reality for most people. However, everyone’s body is different. If you consistently notice symptoms after consuming MSG-containing foods, it’s reasonable to limit your intake. Focus on a balanced diet rich in whole foods, and consult healthcare professionals if you have concerns about food sensitivities or chronic headaches.

Sources:

• U.S. Food and Drug Administration – Questions and Answers on Monosodium Glutamate (MSG)
• National Institutes of Health – The glutamate and the flavor-enhancing monosodium glutamate
• National Institutes of Health – Monosodium Glutamate (MSG): A Review
• Mayo Clinic – Monosodium glutamate (MSG): Is it harmful?
• National Institutes of Health – Prevalence of monosodium glutamate in foods